Dual reflector lighting system

ABSTRACT

A dual reflector lighting system (10) having a housing, a ballast and a lamp socket (16) connected to receive a gaseous discharge or high intensity discharge (HID) lamp (14). An outer reflector (21) is mounted to the housing to reflect a portion of light from the lamp (14). An inner or auxiliary reflector (22) is mounted coaxially with the lamp (14) to reflect a substantial amount of light from the lamp (14) downwardly. The auxiliary reflector (22) is preferably adjustable relative to the lamp (14). The invention also covers a dual reflector assembly, including an outer reflector (21) and inner reflector (22), adjustable relative to each other which is adapted to be mounted to a HID fixture. The invention also covers an auxiliary reflector (22) having a predetermined size and shape adapted to fit within an outer reflector (21) of a HID fixture and preferably includes facilities for adjusting the auxiliary reflector (22) relative to the outer reflector (21).

TECHNICAL FIELD

This invention relates to an dual reflector lighting system or luminairehaving an outer reflector and an auxiliary or inner reflector whichdistributes the light in a certain way to direct a first predeterminedamount of light onto the floor or work area and a second predeterminedamount of light above the work area. The subject invention increases theefficiency of the lighting system so that a fixture with a highintensity discharge (HID) lamp of lower wattage can be used to getsubstantially equal or greater lighting on the work area. Alternatively,a fixture in accordance with this invention which uses the same wattagelamp as a conventional fixture will provide a substantially greateramount of light on the work area. The invention includes a luminairehaving a high intensity discharge lamp, an outer reflector, and anauxiliary reflector mounted within the outer reflector and movablerelative to the lamp for concentrating light in a first work areabeneath the luminaire and providing a certain amount of light outside orabove the first area. The invention also covers a dual reflectorassembly, including an inner and an outer reflector adjustable relativeto each other, the assembly adapted to be mounted to an HID fixture. Theinvention also relates to an auxiliary reflector and bracket assemblyfor retrofitting conventional fixtures, and a retrofit kit forretrofitting conventional fixtures of a specific wattage, to dualreflector systems of lesser wattage.

High bay lighting fixtures are typically used in warehouses andmanufacturing plants. Such lights are generally referred to as highintensity discharge (HID) lights or gaseous discharge lights.Conventional high bay lighting fixtures direct all of the light equallyleaving the areas closest to the fixture too bright and the workingareas furthest from the fixture too dim. In a typical warehouse, lightfixtures will be between 15 to 65 feet above the floor. Most light isusually required at the working surface or floor level, not at the topof the storage racks or near the ceiling. However, the storage racksrequire sufficient lighting to enable workers operating fork lifts tohave sufficient visibility to remove products from the racks and tostore products in the racks. In order to obtain a desired level of lightat the working area with such conventional fixtures, a fixture of higherwattage must be used. This creates overly bright conditions closer tothe ceiling where it is not needed. In installations in warehouses wherethere are rows of racks of merchandise, with aisles therebetween,conventional HID lighting systems typically use 400 watt and 1,000 wattluminaires for such installations. The subject invention permits the 400watt luminaires to be replaced with 250 watt luminaires, and in someinstances, 150 watt luminaires, and the 1,000 watt luminaires to bereplaced by 400 watt luminaires. When such a replacement is made usingthe subject invention, the amount of foot candles measured at the floorlevel is substantially the same, or greater, while the lighting at thetop of the racks may be reduced, but is still more than sufficient forworkers to be able to function. The energy savings resulting from use ofthe lower wattage lamps is typically between 40-65%. This results insubstantial reduction of energy costs. Not only do customers benefit bya reduction in energy costs by replacing 400 watt fixtures with 250 wattfixtures, or even 150 watt fixtures, but, in installations using airconditioning or refrigeration, they also reduce the amount of airconditioning or refrigeration costs incurred by reducing the heat orkilowatt loading of the work space. Furthermore, they obtain an increasein efficiency from personnel working in a building by having an improvedlighting level at the working surface.

BACKGROUND ART

Henderson Jr., et al U.S. Pat. No. 4,173,037 discloses a luminaire lampsupport device in which the lamp socket is adjustably mounted on abracket for adjustment of the socket along a substantially verticalaxis. This enables adjustment of the lamp to different positions toobtain various light distribution patterns. The lamp has an outerreflector and an asymmetric inner reflector which is mounted forrotational adjustment about the vertical axis of the luminaire forproducing asymmetric distribution of reflected light.

Sholtz U.S. Pat. No. 5,178,452 discloses an operating theater lamp witha outer reflector which illuminates the area of operation and anauxiliary reflector having an outer diameter which correspondsapproximately to the inner diameter of the outer reflector and which isarranged inside the outer reflector to deflect a part of the light beamat a steeper or narrow angle into the bottom of a surgical wound.

Wijbenga, et al U.S. Pat. No. 5,251,116 discloses a luminaire forcreating a primary beam and a secondary beam.

Baldwin, et al U.S. Pat. No. 4,943,901 discloses a luminaire withauxiliary reflecting means for reflecting light passing through the topopening and for reflecting such light to illuminate stacked materialalong the edges of the aisle.

Compton U.S. Pat. No. 4,231,080 discloses a luminaire having at leastthree stack reflector members.

Cochran U.S. Pat. No. 1,286,535 discloses a lighting fixture having aouter reflector and a stationary auxiliary reflector.

None of the foregoing prior art lamps have suggested a solution to theproblem of conserving energy in HID fixtures. The cost of energy isrising significantly, and many power companies have offered inducementsin the form of rebates to customers to cut down on their energyconsumption. Lighting engineers have been forced to specify the use of400 watt and 1,000 watt luminaires based on requirements to have aspecified amount of foot candles at the work surface. Notwithstandingthe prior art, no one has recognized the ability to shape and distributethe light pattern in such a way as to concentrate a substantial amountof light onto the work area while leaving a lesser, but stillacceptable, amount of light at the middle and top of the rackssufficient to allow workmen to utilize such racks.

DISCLOSURE OF INVENTION

The present invention fills a need for an energy efficient high baylighting fixture or luminaire which enables fixtures having lamps ofreduced wattage to be used to replace higher wattage lamps and fixturesthereby conserving significant amounts of energy. Typically, thereplacement of a 400 watt luminaire with a 250 watt luminaire willresult in an approximately 40% or greater savings in energy. The presentinvention relates to a luminaire having a high intensity or gaseousdischarge lamp which is mounted with the base up or down in asubstantially vertical position. An auxiliary reflector is mounted tothe luminaire for coaxial movement relative to the lamp and the outerreflector. The auxiliary reflector is adjustable along the longitudinalaxis of the lamp so that a substantial amount of light is reflected fromthe auxiliary reflector onto a first predetermined area while a smalleramount of light is reflected from the outer reflector onto a secondpredetermined area outside the first area or onto the racks or stackedmerchandise which is positioned closer to the luminaire. The firstpredetermined area is an area substantially larger than the outerdiameter of the outer reflector. It is typically an area that is equalto or greater than the width of an aisle and usually averages ten tofourteen feet in diameter.

In one embodiment of this invention, an auxiliary reflector is mountedto a bracket assembly which is clamped to the lamp socket of aluminaire. The auxiliary reflector could also be attached to the outerreflector of the luminaire. The auxiliary reflector fits within theouter reflector of the luminaire and is adjustable vertically toconcentrate a substantial portion of light emanating from the lamp ontoa first area of work surface. The remainder of the light is reflectedfrom the outer reflector onto the racks or onto a second area outside ofthe first area.

In another embodiment of this invention, a dual reflector system isprovided which can be attached to the housing of a conventional HIDfixture. The dual reflector system includes an outer reflector, an innerreflector and adjustment facilities allowing the inner reflector to beadjusted relative to the outer reflector. The assembly may also includea bracket for attachment to the housing of the fixture.

In another embodiment of this invention, a retrofit kit is provided toretrofit HID fixtures of a first wattage to convert them into a HIDfixture of a second lower wattage having an auxiliary reflector inaccordance with this invention. The retrofit kit typically includes anauxiliary reflector and bracket assembly, a ballast suitable for an HIDlamp of lower wattage and, in some cases, the lower wattage lamp itself.

Further aspects of the present invention will become apparent from thefollowing detailed description when considered in conjunction with theaccompanying drawings. It should be understood, however, that thedetailed description and the specific examples while representing thepreferred embodiments are given by way of illustration only.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side elevational view of a luminaire in accordance with thisinvention with the outer reflector and auxiliary reflector bothpartially broken away.

FIG. 2 is a side elevational view with the outer reflector broken awayillustrating an alternative embodiment of the subject invention.

FIG. 3 is a top plan view of the auxiliary reflector and bracket shownin the FIG. 2 luminaire.

FIGS. 3A and 3B are top plan views of the auxiliary reflector andbracket shown in FIG. 3 having square and rectangular outer reflectorsin place thereabout which are broken away in the center portionsthereof.

FIG. 4 is a side elevational view of a luminaire in accordance with thisinvention with the outer and auxiliary reflectors partially broken awayto illustrate the distribution of light achieved in accordance with thisinvention.

FIG. 5A is a side elevational view illustrating an aisle and a pair ofracks alongside the aisle in a warehouse with a 400 watt metal halidelighting system installed illustrating the distribution of light for theprior art.

FIG. 5B is a side elevational view illustrating an aisle and a pair ofracks alongside the aisle in a warehouse with a 400 watt metal halidelighting system illustrating the distribution of light in accordancewith the subject invention.

FIG. 6A is a diagrammatic representation illustrating an aisle and apair of racks alongside in a warehouse with a 400 watt metal halidelighting system illustrating the distribution of light at the workingsurface for the prior art shown in FIG. 5A.

FIG. 6B is a diagrammatic representation illustrating an aisle and apair of racks along side the aisle in a warehouse with a 400 watt metalhalide lighting system in accordance with this invention illustratingthe distribution of light at the working surface using the subjectinvention.

FIG. 7A is a diagrammatic representation illustrating an aisle and racksalong the sides of the aisle in a warehouse with a 250 metal halidelighting system illustrating the distribution of light at the worksurface for the prior art.

FIG. 7B is a diagrammatic representation illustrating an aisle and racksalong the sides of the aisle in a warehouse with a 250 watt metal halidelighting system in accordance with this invention illustrating thedistribution of light at the work surface using the subject invention.

BEST MODES FOR CARRYING OUT THE INVENTION

The following description is of the best presently contemplated modes ofcarrying out the inventions. This description is made for the purpose ofillustrating the general principles of the invention and should not betaken in a limiting sense.

In accordance with the present invention, there is shown in FIG. 1 aluminaire generally designated as 10 having a casing 12 which containsthe ballast (not shown) and a high intensity discharge lamp 14 which ismounted substantially vertically with its base up into a socket 16. Thecasing has a bracket assembly 17 connected thereto which has a pair ofdownwardly extending legs 18. The legs 18 each have a short inwardlyprojecting horizontal section 19 which fits into a slot 20 in a outerreflector 21. The outer reflector 21 may also be fastened to the bracket17 in other ways conventional in the art. The bracket assembly 17 isadjustable by a slot and screw arrangement at 15 to permit initialadjustment of the distribution of light from the outer reflector 21.

While the vertically mounted lamp is often referred to in a base upposition, it can also be used in a base down position for indirectlighting. Thus, light will be reflected upwardly from the lamp onto aceiling from which it is then reflected down. Such lights are used forindirect lighting, for example, in indoor tennis courts, to avoid glareto the players when they look up. Also, while the lamp is described formany types of installations as being vertically mounted, this is meantto distinguish over fixtures using horizontally mounted lamps. The lampneed not be vertical to be used with the subject invention, as long asthe inner reflector is movable coaxially along the axis of the lamp. Forexample, dual reflector HID flood lights in accordance with thisinvention are positioned and used with the lamp at various angles to thevertical. The subject dual reflector assembly is mounted coaxially withthe lamp. This arrangement provides a highly effective flood light whichcan concentrate its light by adjustment of the inner reflector asdescribed herein.

An auxiliary reflector 22 is mounted for movement relative to the mainreflector 21 and lamp 14 by any number of suitable attachment means. Asshown in FIG. 1, in a preferred embodiment, the outer reflector 21 hastwo or more threaded members 23, such as internally threaded rivets,mounted in the top thereof. While a threaded member 23 is shown, it isapparent that it need not be inserted into the outer reflector. If theupper surface of the reflector is thick enough, a hole could be drilledand tapped to receive a screw or bolt. Alternatively, a wing nut, nut orother threaded member could rest on or be secured to the top of theouter reflector 21. A threaded fastener 24, such as a screw or bolt,passes through a corresponding hole 25 in the top of the auxiliaryreflector 22 and screws into each threaded member 23. A spring 26, orother biasing means, could be used to maintain the desired spacingbetween auxiliary reflector 22 and outer reflector 21. Alternatively, anut could be threaded on the fastener 24 and fixed down on top of theauxiliary reflector in place of using a spring. The use of the springmerely facilitates installation and adjustment of the auxiliaryreflector. The threaded portions of the fasteners may be marked withlines or colors to permit the electrician or installer to evenly adjustthe fasteners so that the top of the auxiliary reflector 22 is parallelto and evenly spaced from the top of outer reflector 21.

Instead of using bolts, a tubular member (not shown) could be used toconnect the outer reflector and the auxiliary reflector. The upper endof the tubular member could be threaded to engage a threaded area formedin the top of the outer reflector. The bottom end of the tubular membercould be fixed to the auxiliary member or could also be threaded toengage a threaded area formed in the top of the auxiliary member.

Every gaseous discharge lamp has an arc tube therein which is designatedby the dotted lines 27 in the lamp 14. The adjustability of theauxiliary reflector 22 is preferably between the range of having the topof the auxiliary reflector 22 substantially even with the upper end ofthe arc tube 27 at its upper position as shown by the dotted lineposition in FIG. 1. The lower range preferably has the top of thereflector 22 about even with the midpoint of the arc tube 27 at itslower position, as shown by the lower solid line position of auxiliaryreflector 22 in FIG. 1. The preferred position is about midway betweenthe upper and lower position as shown in FIG. 2 where about one inch ofthe arc tube 27 is above the upper surface 28 of auxiliary reflector 22.Notwithstanding the foregoing, however, it has been found that there areapplications where the top of the auxiliary reflector is positioned wellabove the upper end of the arc tube. In this case, there is stillsubstantial concentration of light onto the work surface by theauxiliary reflector.

The adjustment of the auxiliary reflector 22 relative to the lamp 14 andthe outer reflector 21 depends upon a number of factors, including theheight of the fixture, the type and wattage of lamp used, the distanceto the work surface and the width of the aisles. While the work surfaceis frequently referred to as the floor, it is to be understood that, fortask lighting, the work surface could be a table, or conveyor belt orsome other raised surface on which people are working.

In describing the subject invention, the term "watts" is meant to be theenergy consumed by the source to generate the lumens. The term "lumens"is meant to be the amount of light generated from a source. A lamp oflower wattage will generate lower lumens than a lamp of higher wattage.The term "foot candles" is meant to define the amount of light asmeasured by a light meter at a particular point.

In the subject invention, even though the replacement of a 400 watt lampwith a 250 watt lamp lowers the amount of lumens, it has been found thatthe same or greater foot candles can be measured at the working surface.If the lumens of the lamp are the same, it has been found that, by usinga fixture in accordance with the subject invention, you cansubstantially increase the amount of foot candles measured at theworking area. For example, in a 30' high installation with a 400 wattconventional luminaire, you might measure 10 foot candles at the worksurface. With a fixture in accordance with this invention, foot candlereadings of 40 to 80 foot candles are obtained at the work surface. Thesize of the auxiliary reflector 22 is very important. If the reflectordiameter is too big, you do not get the desired distribution of light atthe working area. If the diameter of the auxiliary reflector is toosmall, you get a concentration of light on the work area. which isvisible as a hot spot. Ideally, hot spots are to be avoided so thatthere is a uniform distribution of light on the work surface or floor sothat people do not notice a significant change in light as they walkfrom one fixture to another. Also, if the diameter of the auxiliaryreflector is sized incorrectly, you may not get the desired amount oflight on the racks above the working area.

The shape of the auxiliary reflector 22 is also very important. If theshape of the auxiliary reflector is such that light is reflected backfrom the auxiliary reflector onto the lamp, particularly in the area ofthe arc tube 27, it raises the temperature of the lamp which increasesits voltage and decreases lamp life. Increased voltage also causes thelamp ballast to break down, hence, this is to be avoided. Consequently,it is desirable that the shape of the auxiliary reflector 22 is suchthat substantially all the light impinging upon the auxiliary reflector22 from the lamp 14 is directed downwardly with little or no reflectionback at the lamp itself. Ideally, the curve of the auxiliary reflectorconcentrates light emanating from the arc tube 27 and reflects itdownwardly at the work area.

The height of the auxiliary reflector 22 is the distance indicated bythe letter H in FIG. 1 between the upper surface 28 of the auxiliaryreflector and the plane of the lower edge surface 29. If the auxiliaryreflector height H is too high, light rays will be reflected back at thelamp 14 and decrease the lamp life as previously described. Also, toomuch light may be directed at the work area, leaving too little light tobe distributed higher at the racks. If the height of the auxiliaryreflector 22 is too small, a sufficient amount of light will not beconcentrated at the work surface.

It has also been found that the heat generated by the lamp 14 causes airto rise and flow into the bottom of the outer reflector 21 and throughthe hole in the top of the outer reflector 21. With the use of anauxiliary reflector 22, it has been found that a venturi effect iscreated between the outside of the auxiliary reflector 22 and the insideof the outer reflector 21 which causes air to flow at increased speedthrough the fixture thereby cooling both the outer reflector 21 and theauxiliary reflector 22. In many cases, the auxiliary reflector 22 iscool enough to touch, even when the lamp has been on for a long periodof time. This air flow also facilitates keeping the reflectorsrelatively clean.

The material of which the auxiliary reflector 22 is made is selected todissipate the heat generated by the lamp 14 which also helps to keep thelamp cool. Preferably, an aluminum material is used.

The desired position of the auxiliary reflector relative to the arc tube27 in the lamp is such that a substantial portion of the light comingfrom the arc tube 27 will be reflected off of the inner surface of theauxiliary reflector 22 and directed downwardly in a desired pattern ontoa first predetermined area, namely, the work surface. The rest of thelight, which strikes the outer reflector 21 from both the top and thebottom of the lamp 14, will be widely dispersed onto a secondpredetermined area which illuminates the sides of the racks or areasabove the immediate work area, or the areas of the work surface outsideof the first predetermined area. It has been found that the auxiliaryreflector 22 can be adjusted so as to eliminate any hot spots on thefloor or work area. Hot spots are areas of greater illumination whichare visible to the human eye. When the auxiliary reflector 22 isadjusted so as to eliminate hot spots, aisles and work areas have arelatively uniform distribution of light thereon.

It has also been found that the preferred location of the auxiliaryreflector 22 is to have the top surface 28 positioned about one inch orso below the top of the arc tube 17. It has been found that when theauxiliary reflector 22 is in this preferred position, the fixture willdraw a lower amount of watts. For example, with a conventional 250 wattmetal halide fixture, the lamp and ballast pulls about 305 watts throughthe line. When an auxiliary reflector 22 is installed in accordance withthis invention and properly positioned with respect to the lamp 14, thelamp and ballast pulls about 296 watts through the line. By decreasingthe watts, the life of the lamp and the ballast is increased and, also,there is an additional energy savings. It is believed that thisreduction in wattage results from a decrease in temperature bypreventing light rays reflected from the outer reflector 21 fromimpinging upon the lamp 14 and, in particular, the arc tube 27 area ofthe lamp. Further, a reduction in temperature is realized by shaping theauxiliary reflector in such a way that little or no light is reflectedfrom the auxiliary reflector 22 back into the arc tube area of the lamp14. Also, the venturi effect previously described helps to reduce thetemperature of both reflectors and, likely, the temperature of the lamp.

While the subject invention is defined as a high bay fixture orluminaire, "high bay" is meant herein to cover any installation wherethe fixture is mounted high off the ground or floor. This would includesuch other applications as street lighting, parking lot lighting,building flood lighting, flood lights, low bays, and sports lighting.Furthermore, while the fixtures shown do not have a lens, panel orshield covering the bottom of the fixture as in dust proof fixtures,such a dust proof fixture could be utilized in accordance with thisinvention. While numerous mention is made of warehouses with racks, itis, of course, evident that the subject invention can be used inapplications where there are no racks, but where there is a desire touse energy efficient lighting and to drive a significant amount of thelight from a fixture mounted high off the floor onto the workingsurface.

While in most cases the outer reflectors are opaque and typically madeof metal, the outer reflectors may also be translucent or transparentand made of acrylic or glass or other materials which allow light topass therethrough. Such acrylic or glass reflectors may reflect littleor no light downwardly. Nevertheless, such reflectors are includedwithin the definition of the term outer reflector as used herein.Consequently, when acrylic or glass outer reflectors are used, theauxiliary reflector is even more necessary and effective inconcentrating a substantial portion of light onto the floor whileallowing the translucent or transparent outer reflector to pass lighttherethrough. Additionally, the outer reflector in many cases has acircular cross section, as does the inner reflector, and the innerreflector is concentric with the outer reflector. This is not necessaryin all applications, however. For example, a square or rectangular outerreflector could be used with an inner reflector having a circular crosssection, as shown in FIGS. 3A and 3B wherein outer reflectors 21a and21b are illustrated. Also, different shapes of inner reflectors couldalso be used in accordance with the principles of this invention.

Referring now to FIG. 2, there is shown an alternative embodiment of thesubject invention in which the auxiliary reflector 22 is mounted to thelamp socket 16 by a bracket assembly 30 instead of directly to the outerreflector 21. In this embodiment, three equidistantly spaced holes aredrilled in the top of the outer reflector 21. Three corresponding holesare formed in the auxiliary reflector 22. As shown in FIGS. 2 and 3,three fasteners 31 which pass through the holes in the auxiliaryreflector and outer reflector connect the auxiliary reflector 22 to thelamp socket 16 and provide stability for the auxiliary reflector 22. Aminimum of two fasteners 31 should be used, although at least three arepreferred for stability. The bracket assembly 30 includes a flexible,metal band 32 which fits around socket 16. The metal band 32 has a pairof projections 33 which can separate to allow installation of the band32 about the socket 16 without removing the lamp 14, if desired. Tosecure or clamp the bracket assembly 30 to the socket 16, theprojections 33 are fastened together by screw or bolt 34 and nut 36 asshown in FIG. 3. The bracket assembly 30 can be adjustably connected tothe socket 16 anywhere along its length. This provides two separateadjustment facilities, one being the bracket assembly 30 and the otherbeing the fasteners 31 as described hereafter. Attached to or formedintegrally with the band 32 are a plurality of L-shaped or outwardlyprojecting brackets 37. The free end of each bracket 37 either has ahole therethrough or a threaded member, such as an internally threadedrivet 35, therein for receiving the threaded end of the fasteners 31.The fasteners 31 are typically adjusted by the electrician or installerfrom inside the auxiliary reflector 22, but, if desired, they can bemounted the other way and adjusted from the top. A plurality of springsor other biasing means could be used as described in FIG. 1 to bias theauxiliary reflector 22 away from the brackets 37 which are clamped tolamp socket 16. As discussed, the auxiliary reflector 22 is adjustedrelative to the lamp 14 so that a significant amount of light from arctube 27 is reflected by the inner surface of the auxiliary reflector 22downwardly to the working area. Normally, the top surface 38 of theauxiliary reflector 22 is positioned near the top of the arc tube 27 andis then adjusted downwardly until hot spots appear. Then, the auxiliaryreflector 22 is then adjusted upwardly until the hot spots disappear.This adjustment provides maximum work area light distribution.

Referring now to FIG. 3, there is shown a top view of the auxiliaryreflector 22. It can be seen that there is an upper flat surface 28 ofthe auxiliary reflector 22 which has a hole 39 therein. The hole 39 ispreferably as small as possible to reflect most light down to the workarea. The size of the hole 39 in an auxiliary reflector 22 for a highpressure sodium lamp is typically about three inches. For a metal halidelamp which has a larger diameter, the hole 39 is typically about fourinches. Too big a hole allows too much light to escape upwardly unlesssuch an effect is desired. Too small a hole prevents lamp adjustment or,if the inner diameter of the hole 39 is too close to the lamp, can causean arc across the lamp.

The inner surface of the auxiliary reflector 22 is preferred to beconcave and smooth from the outside diameter of the upper surface 28down to the outside diameter of the plane of the lower surface 29.Preferably, the inner surface of the auxiliary reflector is polished tomore efficiently reflect light. Other known finishes can also be used.

Referring to FIG. 4, there is shown a representation of theconcentration of the light rays by the auxiliary reflector 22illustrating how the light is concentrated in the work area generallydesignated by the plurality of lines directed downwardly. It can befurther seen that a sufficient amount of light bounces off the outerreflector as illustrated by the light rays which are directed to thesides.

Referring to FIG. 5A, there is shown an example of a typical high baylighting installation with a fixture generally designated as 40 and apair of racks 41 and 42 which are spaced 14 feet apart. The fixture 40is a conventional 400 watt metal halide fixture. The fixture 40 ispositioned 28 feet above the floor of the warehouse, and the spacingbetween fixtures is 25 feet.

In FIG. 5B, the fixture 46 is a dual reflector 400 watt metal halidefixture in accordance with the subject invention. The concentration ofthe light rays at the work surface is evident and illustrates that mostof the light is driven downwardly by the auxiliary reflector to the worksurface.

Referring to FIGS. 6A and 6B, there is shown the same fixtures asdescribed in FIGS. 5A and 5B respectively. Foot candle measurements aretaken on the working area, namely, the floor. These measurements weretaken at night to avoid increased measurements due to natural or ambientlight. In FIG. 6A, the fixtures are designated as 40, and in FIG. 6B,the fixtures of the subject invention are designated as 46. In comparingthe foot candle measurements of FIG. 6B to the foot candle measurementsof FIG. 6A, it is evident that the amount of light distributed to thework area is substantially increased by the use of the subjectinvention. Thus, it is apparent that, with the use of the dualreflector, a substantial amount of light is concentrated at the workarea and is being driven down from the fixture to the floor.

Referring now to FIG. 7A, there is shown a plurality of prior artfixtures 51, each of which is a 250 watt metal halide fixture. In FIG.7B, there is shown a plurality of 250 watt metal halide dual reflectorfixture 52, in accordance with this invention, is shown. The height andspacing are the same as set forth above with respect to FIGS. 5A, 5B, 6Aand 6B. The foot candle readings in FIGS. 7A and 7B, also taken atnight, illustrate that a substantially increased amount of light isconcentrated at the work area in the 7B fixture in accordance with thesubject invention. Furthermore, the foot candle measurements generatedby the 250 watt fixture of this invention in FIG. 7B compare favorablywith the 400 watt prior art fixture 40 measurements shown in FIG. 6A.This illustrates how a 250 watt fixture in accordance with thisinvention can replace a 400 watt conventional fixture.

The subject invention is applicable to any luminaire using a highintensity discharge lamp. including those which are dust proof and havea lens, or shield, at the bottom of the outer reflector. It is alsoapplicable to site lighting and shoeboxes which are usually square orrectangular, but sometimes round, enclosures having a vertically mountedHID lamp and a reflector mounted therein. In such a case, the auxiliaryreflector of this invention can be adapted to be mounted coaxially aboutthe vertically oriented lamp to concentrate light downwardly. Further,adjustment facilities may not be necessary if the height of theinstallation is known, wherein the auxiliary reflector could be fixed inposition at the factory. The auxiliary reflector could be fixed inposition for high bays as well, but this is not practical sincewarehouse and factory ceilings vary greatly in height, and theadjustment facilities allow the installer to optimize the setting of theinner reflector on site. In addition, the subject invention isapplicable to increasing the efficiency of existing fixtures, in whichcase an auxiliary reflector 22 and bracket assembly 30 as shown in FIG.2 could be mounted to an existing fixture to increase the amount oflight distributed onto the working surface. Alternatively, the inventioncan be used to retrofit an existing luminaire by changing its ballastand lamp to a lower wattage and then installing an auxiliary reflector22 and bracket assembly 30 so that a substantially equivalent or greateramount of light could be distributed at the work surface while saving asignificant amount of energy.

This invention also includes a retrofit kit which includes at least anauxiliary reflector, mounting facilities for connecting the auxiliaryreflector to a luminaire, means for adjusting the auxiliary reflectorrelative to the lamp, and a ballast. A new lamp may or may not also beincluded in the retrofit kit. It is well known that lamps in the subjecthigh bay luminaires cannot merely be replaced with a lamp of a lower orhigher wattage. Rather, a new ballast must be installed corresponding tothe type and size of lamp utilized.

Although the present invention has now been described in terms ofcertain preferred embodiments and exemplified with respect thereto, oneskilled in the art will readily appreciate the various modifications,changes, omissions and substitutions may be made without departing fromthe spirit and scope thereof. It is intended that the present inventionbe limited solely by the scope of the following claims:

What is claimed is:
 1. A dual reflector lighting system comprising:ahousing having a ballast and a lamp socket electrically connectedthereto to receive a gaseous discharge lamp; an outer reflector mountedto said housing to reflect a portion of light from said lamp; and anauxiliary reflector mounted within said outer reflector about said lampto reflect a substantial amount of light from said lamp onto a firstpredetermined area substantially larger than the outer diameter of saidouter reflector.
 2. A dual reflector lighting system as set forth inclaim 1 comprising:means for adjusting said auxiliary reflector relativeto said outer reflector.
 3. A dual reflector lighting system as setforth in claim 1 comprising means for adjusting said auxiliary reflectorrelative to said lamp.
 4. A dual reflector lighting system as set forthin claim 1 wherein said auxiliary reflector is concentrically mountedwithin said outer reflector.
 5. A dual reflector lighting system as setforth in claim 4 wherein said outer reflector and auxiliary reflectorare circular in cross section.
 6. A dual reflector lighting system asset forth in claim 2 wherein said outer reflector has at least twothreaded holes therein;said auxiliary reflector has at least two holesin alignment with said holes of said outer reflector; and said adjustingmeans includes at least two elongated threaded members for adjustablyinterconnecting said outer reflector and said auxiliary reflector.
 7. Adual reflector lighting system as set forth in claim 2 including meansfor biasing said auxiliary reflector away from said outer reflector. 8.A dual reflector lighting system as set forth in claim 1 including meansfor connecting said auxiliary reflector to said lamp socket.
 9. A dualreflector lighting system as set forth in claim 8 wherein saidconnecting means includes:a flexible band surrounding said lamp socketand spaced from said auxiliary reflector; means for interconnecting saidflexible band and said auxiliary reflector; and means for securing saidflexible band to said lamp socket.
 10. A dual reflector lighting systemas set forth in claim 1 wherein said lamp has an arc tube therein andsaid auxiliary reflector is positioned to surround a substantial portionof said arc tube.
 11. A dual reflector lighting system as set forth inclaim 1 wherein said lamp has an arc tube therein oriented along thevertical axis of said lamp and the height of said auxiliary reflector isless than the length of said arc tube.
 12. A dual reflector lightingsystem as set forth in claim 11 wherein a substantial amount of thelight emanating from said arc tube is reflected downwardly by saidauxiliary reflector.
 13. A dual reflector lighting system as set forthin claim 1 wherein said outer reflector is rectangular in cross-sectionand said auxiliary reflector is circular in cross-section.
 14. A dualreflector lighting system as set forth in claim 1 wherein said outerreflector is square in cross-section and said auxiliary reflector iscircular in cross-section.
 15. A dual reflector lighting system as setforth in claim 1 wherein said outer reflector allows some transmissionof light therethrough.
 16. A dual reflector lighting system as set forthin claim 3 wherein said outer reflector allows some transmission oflight therethrough.
 17. An auxiliary reflector for gaseous dischargeluminaires having a gaseous discharge lamp and an outer reflectorsurrounding said lamp comprising:an auxiliary reflector having a sizeand shape adapted to fit within the outer reflector and coaxially aboutsaid lamp; and means for connecting said auxiliary reflector to saidluminaire and adjusting said auxiliary reflector along the axis of saidlamp so that a first portion of light is distributed in a first patternsubstantially larger than the diameter of the outer reflector on a worksurface, and a second portion of light is distributed in a secondpattern outside of said first pattern.
 18. An auxiliary reflector as setforth in claim 17 wherein said first pattern is substantially uniform.19. An auxiliary reflector as set forth in claim 17 wherein said firstpattern is substantially circular.
 20. An auxiliary reflector as setforth in claim 17 wherein the auxiliary reflector has a flat uppersurface having a hole therein for receiving the lamp and having aconcave inner surface shaped to direct substantially all of the lightimpinging on the auxiliary reflector downwardly in said first patternonto the work surface.
 21. An auxiliary reflector as set forth in claim17 wherein said lamp is connected to a lamp socket and said connectingand adjusting means comprises a bracket assembly having a first endclamped to said lamp socket, and a second end connected to saidauxiliary reflector.
 22. An auxiliary reflector as set forth in claim 17wherein said connecting and adjusting means includes a plurality offasteners connecting said auxiliary reflector to said outer reflector.23. An auxiliary reflector as set forth in claim 22 wherein saidfasteners are marked to permit uniform adjustment of said fasteners toposition the top of said auxiliary reflector substantially parallel tothe top of the outer reflector.
 24. An auxiliary reflector as set forthin claim 17 wherein said connecting and adjusting means includes meansfor biasing said auxiliary reflector away from said outer reflector. 25.An auxiliary reflector as set forth in claim 21 wherein said connectingand adjusting means includes means for biasing said auxiliary reflectoraway from said end of said bracket assembly clamped to said lamp socket.26. An auxiliary reflector as set forth in claim 17 wherein saidauxiliary reflector is adapted to be mounted concentrically with saidouter reflector.
 27. An auxiliary reflector as set forth in claim 17wherein said gaseous discharge lamp has an arc tube therein, and theheight of said auxiliary reflector is less than the length of said arctube.
 28. An auxiliary reflector as set forth in claim 17 forilluminating an aisle and racks positioned on each side of said aislewherein said first pattern is at least as wide as the width of saidaisle, and said second pattern illuminates the racks above the worksurface.
 29. An auxiliary reflector as set forth in claim 17 comprisinga curved inner surface shaped to reflect substantially all lightdownwardly towards the work surface and substantially no light back atsaid lamp.
 30. A retrofit kit for retrofitting a gaseous dischargeluminaire having a gaseous discharge lamp of a first wattage positionedwithin an outer reflector to accept a gaseous discharge lamp of areduced wattage without decreasing the illumination of the work areaunder said luminaire comprising:a ballast compatible with a specifiedlamp of reduced wattage; an auxiliary reflector adapted to be mounted tosaid luminaire within said outer reflector and coaxially about said lampof reduced wattage; and means for connecting said auxiliary reflector tosaid luminaire and adjusting said auxiliary reflector relative to saidlamp of reduced wattage so that a substantial portion of the lightemanating from said lamp of reduced wattage is concentrated in a firstpredetermined pattern which is substantially larger than the diameter ofsaid outer reflector.
 31. A retrofit kit as set forth in claim 30wherein said kit further includes a gaseous discharge lamp of specifiedtype having a wattage less than said lamp of first wattage.
 32. Aretrofit kit as set forth in claim 30 wherein said luminaire includes alamp socket and said connecting and adjustment means includes a bracketassembly having a first end clamped to said lamp socket and a second endconnected to the top of said auxiliary reflector.
 33. A retrofit kit asset forth in claim 30 wherein said luminaire includes a lamp socket andsaid connecting and adjusting means includes a flexible band adapted tobe clamped about said lamp socket;a plurality of angled bracketsconnected to said flexible band; and a plurality of fasteners, eachhaving one end connected to said auxiliary reflector and the other endconnected to one of said angled brackets.
 34. A retrofit kit as setforth in claim 30 wherein said auxiliary reflector is adapted to bemounted concentrically within said outer reflector.
 35. A retrofit kitas set forth in claim 34 wherein said lamp of reduced wattage has an arctube therein and the height of said auxiliary reflector is less than thelength of said arc tube.
 36. A retrofit kit as set forth in claim 35wherein said auxiliary reflector has a curved inner surface shaped toreflect substantially all of the light impinging on said inner surfacedownwardly towards the work surface.
 37. A retrofit kit as set forth inclaim 30 wherein said outer reflector is rectangular in cross-sectionand said auxiliary reflector is circular in cross-section.
 38. A dualreflector assembly adapted to be mounted to a housing of a lightingfixture having a gaseous discharge lamp comprising:an outer reflector;an inner reflector smaller than the outer reflector and adapted to fitwithin said outer reflector coaxially about said gaseous discharge lampto reflect a substantial amount of light from said lamp onto an areasubstantially larger than the diameter of said outer reflector; andmeans connecting said outer reflector and said inner reflector foradjusting said inner reflector relative to said outer reflector.
 39. Adual reflector assembly as set forth in claim 38 wherein said innerreflector is mounted concentrically within said outer reflector.
 40. Adual reflector assembly as set forth in claim 38 including means forconnecting the outer reflector to said housing of said fixture.
 41. Anauxiliary reflector assembly adapted to be mounted to a lighting fixturehaving a main reflector and a gaseous discharge lamp comprising:anauxiliary reflector; and means for mounting said auxiliary reflector tosaid lighting fixture concentrically within said main reflector in aposition that said auxiliary reflector reflects a first portion of lightfrom said lamp onto a first predetermined area substantially larger thanthe outer perimeter of said main reflector.
 42. An auxiliary reflectorassembly as set forth in claim 41 wherein said mounting means includesmeans for adjusting the position of said auxiliary reflector relative tosaid lamp.
 43. An auxiliary reflector assembly as set forth in claim 41for mounting to a fixture in which the gaseous discharge lamp has an arctube therein, wherein the height of said auxiliary reflector is lessthan the length of said arc tube.
 44. An auxiliary reflector assemblyadapted to be mounted to a lighting fixture having a main reflector, alamp socket and a gaseous discharge lamp comprising:an auxiliaryreflector; and means for connecting said auxiliary reflector to saidlamp socket in a position such that said auxiliary reflector reflects afirst portion of light from said lamp onto a first predetermined areasubstantially larger than the perimeter of the outer reflector.
 45. Anauxiliary reflector assembly as set forth in claim 44 wherein saidconnecting means includes means for adjusting the position of saidauxiliary reflector relative to said lamp.
 46. An auxiliary reflectorassembly as set forth in claim 44 for mounting to a fixture in which thegaseous discharge lamp has an arc tube therein, wherein the height ofsaid auxiliary reflector is less than the length of said arc tube.